SEAWARD MIGRATION OF CHINOOK SALMON. 



15 



One hundred and sixty-six specimens of migrating fry were captured at Point 

 ElHce, July 19, 1916. (See Table 10.) The average length is 92.1 mm., ranging from 

 60 to 1 28 mm., with the mode at 93 mm. It will be noted that here and in the subsequent 

 tables there is very little skewing of the curve of length toward the lower end. This 

 indicates, undoubtedly, that no more of the smallest fry are being added from the upper 

 waters. This is proved by the fact that no fry less than 60 mm. in length were taken. 

 Such fry as are entering the estuary from above must be more nearly the same size as 

 the fish already in the estuary. 



The scales of these fish show an average of 12.9 rings. One hundred and sixteen 

 have started a more rapid intermediate growth, which is indicated on the scales by a 

 marginal band of wider rings. There is an average of 7.6 rings within the intermediate 

 band, the band itself comprising 5.3 rings. Seventy-six of the specimens are males, 

 averaging 90.1 mm. in length. Ninety females average 93.6 mm. 



Table 10. — Fry from Point Elucb, Columbia Estuary, July 19, 1916. 

 fifty specimens without intermediate growth. 



ONE HUNDRED AND SIXTEEN SPECIMENS WITH INTERJIEDIATE GROWTH. 



